A one-foot-long baby squid was spotted swimming in the waters around the South Sandwich islands. The footage is unprecedented ...

Mammals are among the most adaptable animals on the planet. They are found on every continent and in every ocean, and range in size from tiny bumblebee bats to enormous blue whales. One reason for ...

Reptiles first appear in the fossil record 315 million years ago and were the dominant animals during the Mesozoic era, which lasted for 270 million years until the extinction of the dinosaurs.

These solitary, aggressive animals are famous for their ferocious punch—as fast as a bullet and strong enough to snap a crab’s claw. Mantis shrimp live in warm, shallow waters in the Indian ...

Some transport water, oxygen, and carbon dioxide either into or out of the animal. Others fight bacteria or fungal infections. And at least one—in each species—is used for defense. To warn ...

Its brain is proportionally larger than those found in living reptiles, so the animal may have been as intelligent as modern birds, which are more similar in brain size. Troodon walked (and ran ...

Hermit crabs are omnivorous scavengers, eating microscopic mussels and clams, bits of dead animals, and macroalgae. These crustaceans have been misnamed for two reasons: First, they’re not true ...

Birds are vertebrate animals adapted for flight. Many can also run, jump, swim, and dive. Some, like penguins, have lost the ability to fly but retained their wings. Birds are found worldwide and ...

There are reports of giant stingrays weighing up to 1,300 pounds, though such accounts are not verified because weighing the enormous and awkward animals is very difficult. Brown to gray in color ...

The oldest winged fossil dates back 330 million years ago, suggesting that insects were among the first animals to leave the oceans for land during the Devonian period some 400 million years ago.

Tigers and monkeys and tapirs, oh my! Joel Sartore's latest book, "National Geographic Photo Ark: Babies," captures the animal kingdom's most curious youngsters.